testing with to list tests

      cd software/erp5/test

      env PYTHONNOUSERSITE=1 \
          MAKEFLAGS=-j128 \
          SLAPOS_SR_TEST_NAME=erp5-py3 \
          SLAPOS_TEST_SKIP_SOFTWARE_REBUILD=1 \
          SLAPOS_TEST_VERBOSE=0 \
          SLAPOS_TEST_SKIP_SOFTWARE_CHECK=1 \
          SLAPOS_TEST_DEBUG=0 \
          PYTHONWARNINGS=ignore \
          zope-testrunner  --color -vD --path . --tests-pattern test --list-tests

and to run :

      env PYTHONNOUSERSITE=1 \
          MAKEFLAGS=-j128 \
          SLAPOS_SR_TEST_NAME=erp5-py3 \
          SLAPOS_TEST_SKIP_SOFTWARE_REBUILD=1 \
          SLAPOS_TEST_VERBOSE=0 \
          SLAPOS_TEST_SKIP_SOFTWARE_CHECK=1 \
          SLAPOS_TEST_DEBUG=0 \
          PYTHONWARNINGS=ignore \
          zope-testrunner  --color -vD --path . --tests-pattern test

problems:
 - zope.testrunner could support setupModule / setupClass directly (or
    at least the workaround could be put directly in slapos.core testing
    on the default SlapOSInstanceTestCase)
 - zope.testrunner -D trigger debuggers on expected failures (probably similar to
   https://github.com/zopefoundation/zope.testrunner/issues/141 )
 - hitting Ctrl+C seems "even worse" than default unit test -> we can probably
   register a signal handler in setupClass to stop slapos standalone subsystem
   ourselves.
 - nxdtest probably needs support for good reporting on test_result_module

zope.testrunner